1. Field of the Invention
The invention pertains to a method for the extraction of the metallic phase from a dispersed mixture comprised of at least one light metal, particularly aluminum, or from an alloy of light metals and from at least one nonmetallic phase, formed of at least of one oxide or an oxide of an alloy of these metals, if applicable of one or more additional materials, for example salts or salt mixtures and the like at higher temperatures, particularly waste metals or dross resulting from methods for the production, using, as well as the reclamation of aluminum and aluminum alloys and, if applicable, at least the partial separation of the nonmetal phases thereof.
2. Discussion of the Background of the Invention and Material Information
Light metals, such as aluminum, silicon, magnesium and the like, as well as light metal alloys have a very great affinity for oxygen and nitrogen and react with these gases, which essentially form the atmosphere, in the formation of oxides and nitrides.
Aluminum oxide has a higher specific weight than metallic aluminum, whose outer surface tension and interfacial tension as well as the macrostructure of the oxide, however cause a carrying of the oxide particles at the upper surface or the swimming of the waste metals upon the melt.
A melt-metallurgical extraction, production, reclamation and the like of light metals takes place mostly in air, so that thereby reaction products or nonmetallic phases, particularly oxides, are formed at the outer surface of the melting particles and/or of the melting bath and as a result thereof cover the molten metal.
Prior to a tapping or casting of the liquid metal, the waste metal must be stripped and drawn off. Waste metals however always contain, often actually in appreciable quantity, metal in the form of fine droplets in the spaces between the oxide crystals, wherein such a dispersed mixture often can have a metal content of up to 80%. A simple demetallization of a dispersed mixture, comprised of at least one light metal, particularly aluminum, or of an alloy of light metals and from at least one nonmetallic phase, formed of at least one oxide or an oxide of an alloy or other nonmetallic combinations of these metals, if applicable one or more additional materials, for example salts of salt or salt mixtures and the like, at higher temperatures, particularly waste metals resulting from methods for the production, using, as well as the reclamation of aluminum and aluminum alloys and, if applicable, at least the partial separation of the nonmetallic phases of the waste metals, at the usual temperatures above the melting point of the metal is difficult due to the outer surface tension and the structural properties of the nonmetallic phase, whereby the yield of the melting process is reduced and large quantities of metal remain unused.
The known prior methods and mechanism or apparatuses for the demetallization of waste metals or dross are difficult and/or ineffective, since still considerable amounts of metal remain in the residues. Metal-containing dross or else the high metal contents in the remaining materials in the currently industrially utilized metal recovery methods for dross/slag however are a danger for the environment, so that a safe disposal thereof is coupled with high expense.